Her speech was met by furious applause and even some gasps from the audience.

At present in the UK, one in four people has a mental health illness.

Suicide is the biggest killer of men under 21 in Britain and in a typical British classroom, three students are self-harming.

In recent years, mental health services have been severely cut and Ms Devon argued that whichever party wins next year, more must be done to combat such issues.

Speaking exclusively to the Daily Star Online, she said: "Having worked with more than 40,000 students in more than 200 UK schools I know young people, their teachers and parents are struggling with common mental health issues.

"We desperately need government support to redress a situation which will cost the economy billions in the future through lost earnings and strain on the NHS. Our youth need more."

For confidential support about mental health issues call the Samaritans in the UK on 08457 90 90 90 or visit a local Samaritans branch.